Pipe laying in casings
Laying of a carrier pipe through a casing involves:
- the centring and guidance of each component within the casing,
- anchoring the components together, to allow pulling of the section through the casing.
Ductile iron socket pipes may easily be installed through casings.
Before preparing the pipe guide sled:
- clear the accesses to the casing,
- check the condition and alignment of the casing,
- ensure that the size of the guide sled is compatible with the internal diameter of the casing.
Guide sled preparation
Depending on the pipe diameter, the socket diameter and possibly the anchoring gland, use, or construct, the guide sled and centring collars most appropriate for pulling the pipes through the casing. Make sure that the traction load does not exceed the joint resistance.
| DN |
De (mm) |
Maximum traction load (kN) |
||
|---|---|---|---|---|
|
STD Vi C40/C30 |
Univ Vi K9 |
Univ Ve K9 |
||
| 60 |
77 |
12 |
|
|
| 80 |
98 |
17 |
45 |
|
| 100 |
118 |
25 |
61 |
70 |
| 125 |
144 |
36 |
85 |
104 |
| 150 |
170 |
45 |
109 |
136 |
| 200 |
222 |
62 |
166 |
201 |
| 250 |
274 |
94 |
230 |
271 |
| 300 |
326 |
134 |
284 |
342 |
| 350 |
378 |
180 |
281 |
426 |
| 400 |
429 |
231 |
289 |
506 |
| 450 |
480 |
235 |
290 |
579 |
| 500 |
532 |
245 |
356 |
667 |
| 600 |
635 |
317 |
507 |
855 |
| 700 |
738 |
|
|
1155 |
| 800 |
842 |
|
|
1392 |
| 900 |
945 |
|
|
1753 |
| 1000 |
1048 |
|
|
2157 |
| 1100 |
1152 |
|
|
|
| 1200 |
1255 |
|
|
2474 |
Using ANCHORED STANDARD pipes
- Pass a wire rope through the casing and attach it to the first pipe.
- Attach guidance and centring collars behind each socket.
- Pull the first pipe into the casing.
- Joint the spigot into the second pipe.
- Anchor the joint.
Having completed this operation:
- pull the second pipe into the sleeve,
- continue joining ANCHORED STANDARD pipes on until the first pipe emerges from the other end of the casing.
With ordinary STANDARD joint and anchoring cable
- Pass a drag rope through the casing, attached to the anchoring cable.
- Attach guidance and centring collars behind each socket, equipped with a fastening for the drag rope.
- Position the first pipe in the casing.
- Attach the anchoring cable and pull the pipe.
- Joint the spigot into the socket of the second STANDARD pipe.
- Attach the anchoring cable to the second support and continue pulling the pipes.
- Continue joining STANDARD pipes on until the first emerges from the other end of the casing.
- Uncouple the drag rope attached to the first pipe, leaving the anchoring cable in position.
Pressure testing
Before connecting the two ends of the main in the casing to the rest of the system it is advisable to subject it to a pressure test, identical to that for the remainder of the system.